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Institute, where we ask questions -- then we ask the experts to
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and environmental health experts share their ideas, inspiration, and
analysis about toxic chemicals and environmental health policy.

“How could the Arctic, seemingly untouched by contemporary ills, so innocent, so primitive, so natural, be home to the most contaminated people on the planet? I had stumbled upon what is perhaps the greatest environmental injustice on earth.”—Marla Cone, author of Silent Snow: the Slow Poisoning of the Arctic

More than 25 years ago, scientists made the unexpected discovery that levels of persistent organic pollutants (POPs) in the breast milk of Nunavik Inuit women in Arctic Canada were seven times higher than in the breast milk of women of southern Quebec.[1] This discovery prompted international action to address POPs contamination as a global issue because it demonstrated the capacity of these chemicals to harm people who live in a region of the world that is far distant from areas of production and use.

POPs are a class of synthetic chemicals including banned or restricted “legacy” chemicals such as PCBs, as well as currently used and emerging chemicals such as brominated flame retardants. The Arctic acts as a “cold trap” and is a hemispheric sink for POPs that are transported through a process known as global distillationvia prevailing atmospheric and oceanic currents from warmer regions.[2] POPs bioaccumulate in the lipid-rich Arctic food webs, some to dangerous levels.[3] Thus, the Arctic is an important indicator region because the presence of chemicals here serves as a warning sign to policy makers that there is a need for protective action on national and international levels.

Following the revelation that Arctic Indigenous Peoples are among the most highly exposed people to POPs, countries of the world came together to negotiate what would become the Stockholm Convention on Persistent Organic Pollutants (the “POPs treaty”), a global legally-binding treaty signed by 152 nations in 2001. The POPs treaty includes provisions to eliminate the production and use of twelve initial chemicals known as the “dirty dozen." However, the real strength of the treaty is that it also includes provisions to add new chemicals that meet scientific criteria for persistence, long-range transport, bioaccumulation, and adverse effects. The Preamble of the Convention also acknowledges that “Arctic ecosystems and indigenous communities are particularly at risk because of biomagnification of persistent organic pollutants and that contamination of their traditional foods is a public health issue.”[4] The Stockholm Convention is now ratified by 179 nations of the world and provides a powerful tool to address chemicals that warrant global action.

Brominated flame retardants are chemicals added to products such as furniture foams, insulation, and electronics to make them fire resistant. Brominated flame retardants are now known to increase fire toxicity without proven benefits to fire safety and are associated with a range of serious health effects in animals and people.[5] The Stockholm Convention specifies that substances may qualify as POPs if they are subject to long-range transport far from source areas. Indeed, results from studies investigating the status and trends of POPs in the Arctic were major factors in the decisions to include four brominated flame retardants under provisions of the treaty and to require steps toward global elimination. In 2009, the nations of the Convention decided to list hexabromobiphenyl (a component of polybrominated biphenyls or PBBs, used in plastics for electronic products and in auto upholstery foams), as well as two polybrominated diphenyl ethers (PBDEs), pentabromodiphenyl ether (Penta-BDE—used in furniture foam) and octabromodiphenyl ether (Octa-BDE—used in plastics for electronic products).[6] In April 2013, hexabromocyclododecane (HBCD), a flame retardant used in polystyrene foam insulation, was listed under provisions of the Convention for global phase-out. And in October 2013, the expert scientific committee of the Stockholm Convention determined that another PBDE known as deca-BDE, used in polystyrene plastics for electrical equipment, met the scientific criteria for inclusion under the Convention and will be advanced to the next evaluation stage.

PBDEs are now ubiquitous contaminants in Arctic biota, from plankton to polar bears, as well as humans. Deca-BDE levels in the Arctic atmosphere are increasing rapidly, with a doubling time of 3.5-6.2 years.[7] Levels of deca-BDE are increasing in certain Arctic species such as peregrine falcons.[8] HBCD is also ubiquitous in the Arctic environment and now found in Arctic birds of prey, marine fish, seabirds, ringed seals, beluga whales, and polar bears.[9] Ikonomou et al. (2002) reported an exponentially increasing trend of PBDE concentrations in Arctic ringed seals and predicted that at “current rates of bioaccumulation, that PBDEs will surpass PCBs to become the most prevalent organohalogen in Canadian Arctic ringed seals by 2050.”[10] Killer whales off the coast of Alaska have the highest levels of PBDEs when compared to other marine mammal species in the circumpolar Arctic and with similar high concentrations in Faroe Island long-finned pilot whales.[11]

PBDE concentrations found in maternal blood serum of Yupik women within the Yukon-Kuskokwim Delta area of Alaska are the highest known human PBDE levels in the Arctic.[12] Indigenous peoples who rely on marine foods as the basis for their traditional diets in the Arctic are at particular risk from contaminant exposure. Many POPs, including flame retardants, are present at elevated and biologically relevant levels in the Arctic.[13],[14],[15] The traditional diet provides critical cultural and public health benefits, but it is also a primary source of exposure to POPs, which pose health risks even at low chronic exposure levels. Although consumption of traditional foods high in omega-3 fatty acids and other nutritional qualities may confer significant cultural and public health benefits, exposure to POPs contaminants may also increase risk for diabetes, hypertension, adverse neurological effects, osteoporosis, thyroid disorders, developmental disorders, and certain malignancies.[16],[17] Exposure to PBDEs has been linked with neurodevelopmental and endocrine disruption in animal and human studies. Elevated levels of PBDE exposures during pregnancy in women are also associated with changes in maternal thyroid hormone levels, decreased fertility, and lower birth weight babies.[18]

In addition to the PBDEs and HBCD discussed above, monitoring studies in the Arctic find other brominated and chlorinated flame retardant chemicals, demonstrating that they are persistent and subject to long-range transport. These include a veritable alphabet soup of substances that the chemical industry is using as regrettable substitutes for flame retardants that are being phased out. These include some of the replacement fire retardant chemicals such as components of Firemaster 550 (EH-TBB and BEHTBP);[19] decabromodiphenyl ethane (a substitute for deca-BDE); TCEP (Tris (2-chloroethyl) phosphate—used in foams in strollers, nursing pillows, couches and chairs), and replacement chemicals for penta- and octa-BDE, including tetrabromobisphenol A (TBBPA), 1,2-dibromo-4(1,2-dibromoethyl)cyclohexane (TBECH), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), hexabromobenzene ((HxBBz), pentabromoethylbenzene (PBEB).[20] Although the toxicology of these and other flame retardant chemicals is poorly understood, the fact that they are present in the Arctic should be cause for state, national, and international regulatory action.